Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C215/00—Compounds containing amino and hydroxy groups bound to the same carbon skeleton
  • C07C215/02—Compounds containing amino and hydroxy groups bound to the same carbon skeleton having hydroxy groups and amino groups bound to acyclic carbon atoms of the same carbon skeleton
  • C07C215/04—Compounds containing amino and hydroxy groups bound to the same carbon skeleton having hydroxy groups and amino groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being saturated
  • C07C215/06—Compounds containing amino and hydroxy groups bound to the same carbon skeleton having hydroxy groups and amino groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being saturated and acyclic
  • C07C215/08—Compounds containing amino and hydroxy groups bound to the same carbon skeleton having hydroxy groups and amino groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being saturated and acyclic with only one hydroxy group and one amino group bound to the carbon skeleton
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C213/00—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton
  • C07C213/02—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton by reactions involving the formation of amino groups from compounds containing hydroxy groups or etherified or esterified hydroxy groups

Definitions

• This invention relates to a method of producing N-­alkylaminophenols which are suitably used as intermediates for the production of heat or pressure sensitive dyes, xanthene dyes or fluorescent dyes.
• an improvement in the production of an N-alkylaminophenol which comprises the reaction of a divalent phenol with an alkylamine to provide a reaction mixture and recovering the N-alkylaminophenol from the reaction mixture, the improvement comprising:
• the divalent phenol used in the invention is preferably represented by the general formula (I) : and they may be exemplified by, for example, resorcinol or hydroquinone.
• the alkylamine used in the invention is preferably represented by the general formula (II) : wherein R1 and R2 represent independently a hydrogen or an alkyl of 1-6 carbons with both R1 and R2 being not hydrogens.
• the alkylamine thus includes a primary amine and a secondary amine.
• the primary amine may be exemplified by, for example, methylamine, ethylamine, n-propylamine, isopropylamine, n- butylamine, isobutylamine, n-amylamine, isoamylamine or cyclohexylamine
• the secondary amine may be exemplified by, for example, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-­butylamine, diisobutylamine, di-n-amylamine, diisoamylamine or dicyclohexylamine.
• N-alkyl- or N,N-dialkylaminophenol as represented by the general formula (III) as shown below: wherein R1 and R2 are the same as before.
• R1 and R2 are the same as before.
• N-alkylaminophenyl involves N,N-dialkylaminophenol.
• the alkylamine is used in a molar ratio of the alkylamine to the divalent phenol of 0.4-1.2, preferably in a molar ratio of 0.5-1.0, not only to increase the conversion rate of the divalent phenol but also to suppress the production of by-products such as phenylenediamines and to improve the selectivity of the reaction to the N-alkylaminophenol.
• the reaction is carried out at a temperature preferably of 120-210°C, more preferably of a temperature of 130-200°C , to raise the reaction efficiency and to suppress the production of by-products such as a tar material.
• the above reaction temperature also enables the reaction under a low pressure.
• the reaction may be carried out under a pressure of from normal pressure to 40 Kg/cm2G, preferably of a pressure in the range of 3-20 Kg/cm2G, under an inert gas atmosphere such as nitrogen, over a period of 1-5 hours, preferably of 2-4 hours.
• the amination reaction is carried out in the absence of a solvent, however, there may be used an organic solvent, if necessary, which is inactive in the reaction such as phenolic solvents.
• the amination reaction is effected in the absence of a catalyst, however, a catalyst may be used, if necessary.
• the catalyst usable includes, for example, phosphoric acid salts, ammonium salts or acetic acid salts.
• these catalysts are used in the amination reaction, they are separated prior to the procedures for the purification and recovery of the N-­alkylaminophenol.
• the invention is not specifically limited in the method of separating and removing the catalyst from the reaction mixture. Thus the catalyst may be separated by, for instance, filtration, layer separation or extraction, according to the catalyst used.
• the acid may be any acid either inorganic or organic provided that it can form a water soluble salt with the N-alkylaminophenol.
• an inorganic acid such as hydrochloric acid, sulfuric acid or phosphoric acid
• an organic acid such as p-toluene-­ sulfonic acid or methane sulfonic acid, among which is preferred a mineral acid such as hydrochloric acid or sulfuric acid.
• the acid is used in a molar ratio of the acid to the N-alkylaminophenol usually of 0.5-2, preferably of 0.7 - 1.5, as an aqueous solution usually of a concentra­tion of 20-80 % by weight, preferably of a concentration of 30-70 % by weight.
• the addition of the aqueous solution of an acid to the reaction mixture provides a two-phase mixture composed of an aqueous phase which contains a water soluble acid salt of the resultant N-alkylaminopenol and an organic phase which contains an unreacted divalent phenol.
• the two-phase mixture is then extracted with an organic solvent so that the unreacted divalent phenol and the other materials soluble in the organic solvent are separated into the organic solvent, to leave an aqueous solution which contains the water soluble acid salt of N-alkylaminopenol.
• the organic solvent used is such that the divalent phenol used is highly soluble therein, and accordingly the solvent includes, for example, a ketone or an ether. More specifically, there may be mentioned as such a ketone, for example, methyl n-propyl ketone, methyl n-butyl ketone, or methyl isobutyl ketone, and as such an ether, for example, diethyl ether, diisopropyl ether or di-n-butyl ether.
• a ketone for example, methyl n-propyl ketone, methyl n-butyl ketone, or methyl isobutyl ketone
• an ether for example, diethyl ether, diisopropyl ether or di-n-butyl ether.
• the extraction is carried out in such a manner that an organic solvent is added to the two-phase mixture in a weight ratio of the organic solvent to the unreacted divalent phenol in the mixture of 0.1-2, preferably of 0.5-1.5 per a single extraction operation, at a temperature of from normal temperature to 100°C .
• This extraction procedure is repeated several times, if necessary, so that substantially all the unreacted divalent phenol and the other materials soluble in the solvent are extracted into the solvent.
• An aqueous solution of an alkali is then added to the aqueous solution separated from the organic phase to adjust the solution at a pH of about 5-9, preferably of 6-8, to neutralize the acid salt and to liberate free N-­alkylaminopenol as an oily layer.
• the alkali is preferably sodium hydroxide and is used as an aqueous solution of a concentration of 5-50 % by weight, preferably of 10-40 % by weight.
• the liberated free N-alkylaminophenol may be separated by extraction with an organic solvent usually at a temperature from normal temperature to 100°C, preferably of 30-60°C.
• the extraction efficiency may be improved by adjusting properly the concentration or amount of the alkali solution used, or by adding a neutral salt to the aqueous solution.
• the oily layer is directly separated from an aqueous layer.
• the separated oily phase is mainly composed of the N-alkylaminophenols, and pure N-alkylamino­phenols are recovered by distillation of the oily phase, The distillation is carried out preferably at a bottom temperature of from normal temperature to 180°C under from normal pressure to a reduced pressure of about 10 mmHg.
• the recovered unreacted divalent phonol may be reused as it is for the amination reaction, or may be distilled to remove the solvent therefrom, and further purified for reuse in the amination reaction.
• an aqueous solution of an alkali is added to the reaction mixture to provide a two-­phase mixture composed of an aqueous phase which contains a water soluble alkali salt of the unreacted divalent phenol and an organic phase which contains the resultant N-alkylaminophenol.
• the aqueous alkali solution used is preferably a solution of sodium hydroxide of a concentration of 5-50 % by weight, preferably of 10-40 % by weight.
• the alkali is used in an amount of 1-3 equivalents, preferably of 1.5-2.5 equivalents per mole of the unreacted divalent phenols.
• the two-phase mixture is extracted with an organic solvent to separate the N-alkylaminophenol and the other organic materials soluble in the solvent as an organic solution.
• the organic solvent used is such that aminophenols are highly soluble therein, and accordingly the solvent includes, for example, a ketone or an ether. More speci­fically, there may be mentioned as such a ketone, for example, methyl n-propyl ketone, methyl n-butyl ketone, or methyl isobutyl ketone, and as such an ether, for example, diethyl ether, diisopropyl ether or di-n-butyl ether.
• a ketone for example, methyl n-propyl ketone, methyl n-butyl ketone, or methyl isobutyl ketone
• an ether for example, diethyl ether, diisopropyl ether or di-n-butyl ether.
• the extraction is carried out in such a manner that an organic solvent is added to the mixture in a weight ratio of the organic solvent to the N-alkylaminophenol in the two-phase mixture of 0.1-2, preferably of 0.5-1.5 per a single extraction operation, at a temperature of from normal temperature to 100°C.
• This extraction procedure is usually repeated several times, so that substantially all the resultant N-alkylaminophenol and the other materials soluble in the solvent are extracted into the solvent.
• the separated organic solution is mainly composed of N-alkylaminophenol, and the distillation of the solution provides pure N-alkylaminophenols.
• the distillation is carried out preferably at a bottom temprature of from normal temperature to 180°C under from normal pressure to a reduced pressure of about 10 mmHg.
• the aqueous alkali solution separated from the organic phase is adjusted at a pH of about 5-9, preferably of 6-8 by adding thereto an aqueous solution of an acid, to neutralize the alkali salt of the unreacted divalent phenol, to liberate a free divalent phenol as an oily layer.
• the aqueous acid solution is preferably a solution of sulfuric acid or hydrochloric acid of a concentration of 30-70 % byweight.
• the liberated free divalent phenol is separated, or extracted and then distilled, for reuse in the amination reaction.
• the amination reaction is carried out in a high conversion rate and the production of undesirable by-products is reduced, so that a high reaction efficiency is achieved. Further, since the obtained reaction mixture is efficiently purified according to the invention, a high purity N-alkylamino­phenol is readily obtained.
• the autoclave was pressurized to 10 Kg/cm2G. Then the autoclave was heated to 170°C and the reaction was carried out under stirring at 170°C over three hours.
• the reaction product was a viscous liquid which was found to contain 38.9 % by weight of resorcinol, 56.5 % by weight of N-ethyl-m-aminophenol and 1.4 % by weight of N,N′-diethyl-m-phenylenediamine.
• the conversion rate of resorcinol was 54.9 mol %
• the selectivity of N-­ethyl-m-aminophenol was 95.7 mol %
• the selectivity of N,N′-diethyl-m-phenylenediamine was 2.0 mol %.
• the oily phase was distilled on an oil bath at a temperature of 160-170°C under a reduced pressure of 4-14 mmHg, to provide 55.7 g of N-ethyl-m-aminophenol having a purity of 96.6 %.
• the amination reaction was carried out to a conver­sion rate of resorcinol of 62 mol % in the same manner as in the Example 1.
• the selectivity of N-ethyl-m-aminophenol was found 86 mol %.
• the amination reaction was carried out at 160 °C and otherwise in the same manner as in the example 1.
• the reaction product was a viscous liquid which was found to contain 43.5 % by weight of resorcinol, 53.2 % by weight of N-ethyl-m-aminophenol and 1.1 % by weight of N,N′-­diethyl-m-phenylenediamine.
• the conversion rate of resorcinol was 50.4 mol %
• the selectivity of N-ethyl-m-­aminophenol was 96.6 mol %
• the selectivity of N,N′-­diethyl-m-phenylenediamine was 1.7 mol %.
• the oily phase was distilled in the same manner as in the Example 1, to provide 51.1 g of N-ethyl-m-amino­phenol having a purity of 97.5 %.
• the reaction product was a viscous liquid which was found to contain 46.5 % by weight of resorcinol, 46.4 % by weight of N-methyl-m-aminophenol and 1.2 % by weight of N,N′-dimethyl-m-phenylenediamine.
• the conversion rate of resorcinol was 49.2 mol %
• the selectivity of N-­methyl-m-aminophenol was 92.9 mol %
• the selectivity of N,N′-dimethyl-m-phenylenediamine was 2.2 mol %.
• the aqueous solution separated from the oily phase was neutralized with a 50 % aqueous solution of sodium hydroxide and was then extracted with 10 g of methyl isobutyl ketone.
• the recovery rate of N-methyl-m-amino­phenol into the ketone was 94.5 %.
• the distillation of the methyl isobutyl ketone extract provided N-methyl-m-­aminophenol having a purity of 92.5 %.
• the reaction product was a viscous liquid which was found to contain 54.3 % by weight of resorcinol, 42.8 % by weight of N-methyl-m-aminophenol and 1.2 % by weight of N,N′-dimethyl-m-phenylenediamine.
• the conversion rate of resorcinol was 42.4 mol %
• the selectivity of N-methyl-m-­aminophenol was 95.8 mol %
• the selectivity of N,N′-­dimethyl-m-phenylenediamine was 2.4 mol %.
• the aqueous solution separated from the ketone extract was neutralized with a 50 % aqueous solution of sodium hydroxide and was then extracted with 10 g of methyl isobutyl ketone.
• the distillation of the methyl isobutyl ketone extract provided N-methyl-m-aminophenol having a purity of 98 %.
• the reaction product was a viscous liquid which was found to contain 45.3 % by weight of resorcinol, 40.6 % by weight of N-methyl-m-aminophenol and 0.8 % by weight of N,N′-dimethyl-m-phenylenediamine.
• the conversion rate of resorcinol was 48.5 mol %
• the selectivity of N-­methyl-m-aminophenol was 85.0 mol %
• the selectivity of N,N′-dimethyl-m-phenylenediamine was 1.6 mol %.
• the autoclave was pressurized to 10 Kg/cm2G. Then the autoclave was heated to 160°C , and the reaction was carried out under stirring at 160°C over two hours.
• the reaction product was a viscous liquid which was found to contain 46.7 % by weight of resorcinol, 44.1 % by weight of N-methyl-m-aminophenol and 0.9 % by weight of N,N′-dimethyl-m-phenylenediamine.
• the conversion rate of resorcinol was 46.2 mol %
• the selectivity of N-­methyl-m-aminophenol was 88.3 mol %
• the selectivity of N,N′-dimethyl-m-phenylenediamine was 1.5 mol %.
• the obtained ketone extract was distilled at a bottom temperature of 160-170°C under a reduced pressure of 4-14 mmHg to remove the methyl isobutyl ketone to provide 55.7 g of N-methyl-m-aminophenol having a purity of 81.4 %.
• the amination reaction was carried out to a conver­sion rate of resorcinol of 62 mol % in the same manner as in the Example 1.
• the selectivity of N-methyl-m-aminophenol was found 86 mol %.
• the amination reaction was carried out in the same manner as in the Example 1. After the reaction, 113 g of a 30 % aqueous solution of sodium hydroxide was added to the reaction mixture, and extraction was effected at 50°C.
• Isopropyl ether was used as an extracting solvent and the extraction was carried out at 50°C, and otherwise in the same manner as in the Example 1, the reaction and consequent purification was carried out.
• the extraction rates of N-methyl-m-aminophenol, resorcinol and N,N′-­dimethyl-m-phenylenediamine into isopropyl ether were 47.6 %, 4.5 % and 100 %, respectively.
• the removal of the isopropylether from the extract by distillation provided N-methyl-m-aminophenol having a purity of 61.8 %.
• n-Octanol was used as an extracting solvent and the extraction was carried out at 50°C , and otherwise in the same manner as in the Example 1, the reaction and consequent purification was carried out.
• the extraction rates of N-­methyl-m-aminophenol, resorcinol and N,N′-dimethyl-m-­phenylenediamine into n-octanol were 92.0 %, 15.8 % and 100 %, respectively.
• the removal of the isopropyl ether from the extract by distillation provided N-methyl-m-aminophenol having a purityof 81.3 %.
• the amination reaction was carried out in the same manner as in the Example 1. After the reaction, 84.9 g of a 30 % aqueous solution of sodium hydroxide was added to the reaction mixture, and extraction was effected using ethyl acetate as an extracting solvent at 50°C.
• the extraction rates of N-methyl-m-aminophenol, resorcinol and N,N′-dimethyl-m-phenylenediamine into ethyl acetate were 82.7%, 2.3 % and 100 %, respectively.
• the removal of the ethyl acetate from the extract by distillation provided N-­methyl-m-aminophenol having a purity of 94.8 %.
• the extraction was carried out at 70°C , and otherwise in the same manner as in the Example 2, the reaction and consequent purification was carried out.
• the extraction rates of N-methyl-m-aminophenol, resorcinol and N,N′-­dimethyl-m-phenylenediamine into methyl isobutyl ketone were 79.7 %, 0 % and 100 %, respectively.
• the removal of the methyl isobutyl ketone from the extract by distillation provided N-methyl-m-aminophenol having a purity of 97.5 %.
• a 50 % aqueous solution of sulfuric acid was added to the aqueous layer separated from the ketone layer and the resultant aqueous mixture was extracted twice with methyl isobutyl ketone, to recover resorcinol having a purity of 99 %.

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• 1990
  • 1990-06-15 US US07/538,719 patent/US5113018A/en not_active Expired - Fee Related
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  • 1990-06-15 EP EP19900111332 patent/EP0402935A3/de not_active Ceased
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